of westminster



T. S. DUNCAN. STARTING OF INTERNAL COMBUSTION ENGINES.

APPLICATION FILED APR,25,191.9.

1,809,722. Patented Jul 15, 1919.

2 SHEETS-SHEET I.

-- T. S. DUNCAN.

smmne or INTERNAL CIOMBUSHON ewmwes.

APPLICATON FILED APR,25 1919 Patented July 15, 1919.

2 suzns-snen 2.

residing at Vickers House,

THOMAS SMITH DUNCAN, OI

WESTMINSTER, LONDON, ENGLAND, ASSIGNOB T VICKEBS LIMITED, OFWESTMINSTER, LONDON, ENGLAND. v

STAB-TING O1 Specification of Letters Patent.

mimmcounusrron rmenms.

Application filed April 25, 1919. Serial No. 292,053.

To all whom it may concern.-

Be it known that I, THOMAS SMITH Dun-- can, a subject of the King ofGreat Britain,

Broadwa ,Westminster, in the county of London, 11 land, have inventedcertain new and usefu Improvements in or Relatin to the Starting ofInternal-Combustion ngines, of which the following is a specification.

This invention relates starting internal combustion engines of the kindin which a clutch member is moved into engagement with a clutch memberon the engine shaft, by means of a helically grooved or screw threadedspindle or the like, the arrangement bein such that after the engine hasbeen starte it will over-run "the helically grooved spindle so that theenaging clutch members are automatically disengaged. The presentinvention has par ticular reference to the starting of aircraft engines,which are arranged in" pairs, for example one pair on eachside of thefuselage naselle.

Accordin to this invention we interpose between eac pair of engines astarting apparatus com rising two co-axially arrang clutch mem rsadapted to move into engagement with clutch members associa with engineshafts, by means of a hel cally ooved or screw threaded spindle which isrotated in any appro riate manner. The helically grooved spin 1e may berotated in eitherdirection by an electric motor through worm gearing andone or other of the said clutch members w1ll be moved into engagementwith the clutch members on the engine shaft according to the directionof rotatlon of the electric motor and the helically grooved spindle.Thus the engines may be started in succession and after. each e 'ne hasstarted, the en g clutch mem ers will be automatically disc ed by theengine overrunning the helica grooved spindle and the electric motor. Insome cases the clutch members may be moved together inoppositedirections to engage simultaneously with the engine shaft, so that theengines are started together.

In order that the said invention may be clearly understood and readilycarried into effect the same will now be described-more fully withreference to the accompanying drawings, in which to apparatus for Figure1 is a diagrammatic sectional view of one construction for starting insuccession a pair of engines having coaxial shafts.

Fig. 2 is a sectional view of a modified Patented July 15,- 1919.

construction also for successivel starting a pair of engines havingco-axial s afts.

Fig. 3 is a vertical sectional view taken on the line 33 of Fig. 2.

In the examples shown A and B repre sent the co-axial shafts of the twoengines. Between the two ends of the shafts A, B and co-axial therewithis a worm wheel C mounted in a suitable bearing and adapted to berotatedby a worm D which is actuated in any suitable manner such as for exampleby a small electric motor (not shown in Fig. 1). In Fi 1, a screw sindle E having a helical threa or groove of quick pitch extends throughand engages with a screw threaded portion at the center of the wormwheel C. On the ends of the screwed spindle E are friction cone clutchmembers F and G, adapted to engage respectively with clutch members H Ion the ends of the engine shafts A B. Supposing it is desired to startthe engine, the worm wheel'C is rotated in one direction and the spindleE is thereby moved longitudinally so as to cause the clutch member (sayF) to engage with the memberH on the shaft 'A thus start the engine.

When the engine has been properly started the shaft A will over-run thestarting motor and the spindle E .in rotating faster than the worm wheelC moves in the opposite longitudinal direction and the clutch mem- .berF is thereby automatically disengaged from the member H. The otherengine can then be started by rotating the worm wheel in the opposite drection whereupon a simi,

lar operation takes place to that above described.

v Spring brakes J bear on the clutch members G actually engages witheither the members i H or I. -In this arrangement the shafts of wheel soas to provide a frictiondrive for F G to prevent rotation of the spindleI .E until either of the clutch members F or transmitting the motion ofthe worm wheel to the spindle when the worm is operated by the electricmotor K which is conveniently supported in a part of the casing of thegearing, see Fig. 3. The spindle E is provided at its ends withhelically grooved portions E with which engage suitabl formed sleeves F,G having end teeth F, forming dog or jaw clutch members forengaging withsimilar clutch members H and I on the ends of the co-axial shafts'A andB of the two engines, when the worm wheel is rotated in one direction orthe other.

Spring brakes J J bearon the said clutchsleeves .to prevent rotation ofthe same until actually in engagement with the clutch members H I. Therotation of the spindle E in one direction auses one of the clutchsleeves say F, to be thrust outwardly into engagement with the member Hby reason of the interengaging helical grooves or the like and whenengagement 1s effected the sleeve is no longer held against rotation bythe springs with the result that the engine shaft A is rotated and theengine started. When the engine shaft A overruns the starting motor Kthe clutch member F, in rotating faster than the spindle E isautomatically disconnected from the engine shafts. When the motor K andthe spindle E is rotated in the opposite direction, the other clutchsleeve G is moved outwardly to start the other engine and isautomatically disengaged in the manner aforesaid.

The apparatus may be devised for start ing two engines simultaneously inwhich case portions such as E are formed with oppositely cut helicalgrooves and the clutch sleeves are formed accordingly, so that rotationof the spindle in one direction moves the clutch members simultaneouslyto effect starting of the engines together.

What I claim and desire to secure by Letters Patent of the United Statesis 1. Starting apparatus for a pair of internal combustion engines,comprising two co-axially arranged clutch members adapted to be movedinto engagement with clutch members associa-ted'with' the engine shaftsby means of a helically grooved or screwthreaded spindle, which isadapted to be rotated to effect the necessary movement of the clr chmembers when starting the en or the like for moving the clutch membersinto engagement with the engine shafts,

and an electric motor for rotating the spindle to cause the one or otherof the clutches to engage with the corresponding engine shafts accbrdingto the direction of rotation of the motor substantially as described.

3. Starting apparatus for a pair of internal combustion enginescomprising a spindle having screw threads or helical grooves at its endsto receive clutch members which when the spindle is rotated will bemoved longitudinally to engage with the engine shafts, substantially asdescribed.

4. Starting apparatus for a pair of internal combustion enginescomprising a spindle, two clutch members mounted on opposite helicallygrooved ends of the spindle, and means for holding the members againstrotation until said clutch members engage other clutch members on saidengine shafts, substantially as described.

5. Starting apparatus for a pair of coaxial internal combustion enginescomprisin a screw threaded or helically grooved spindle adapted to berotated by plates carried thereon, said spindle having clutch membersmounted on its ends adapted to move longitudinally and engage the engineshaft when the s indle is rotated, substantially as described? 6.Starting apparatus for a pair of 00- axial internal combustion enginescomprising a spindle having screw threads or helical grooves at its endsupon which clutch members are mounted, one of said members adapted toengage the clutch member of one of said engines, when the spindle isrotated in one direction, and the other of said clutch members adaptedto engage the clutch mem ber of the other of said engines when thespindle is rotated in the opposite direction.

In testimony whereof I aflix my signature.

THOMAS SMITH DUNCAN.

